Hi DTIPrep developers,

I am using DTIPrep Version 1.2.8.

My DWI data is composed of 30 directions of b=1200 shell and 60 directions of b=2400 shell. I ran a DTIPrep QC check over all my subjects. I want to compare the FA/MD maps between DTIPrep pipeline and a standard FSL DITFIT pipeline (bet, eddt_correct, linear dtifit) to see how much FA/MD maps are affected by the correction.

I have 2 questions:

1 - Is it possible to calculate FA/MD values in DTIPrep by only using one shell data (b=1200) by quality checking on the whole dataset?

2 - How can I export the FA/MD maps from the *_QCed.nrrd file to NIFTI fileformat?

I used the Slicer DWIConvert NRRD2FSL option bu it gave me the following error:

======= DWI Convert Tool Program=========
INPUT VOLUME: ~/QC/checked/p1_QCed.nrrd
Error: ReadVolume: Unsupported source pixel type.
Input volume: unsigned_short
Output volume: short
The only supported output type is . You may consider using allowLossyConversion option.
However, use this option with caution! Conversion from images of a different type may cause data loss due to rounding or truncation.
terminate called after throwing an instance of 'itk::ExceptionObject'
what(): /work/Stable/Slicer-4101-build/BRAINSTools/DWIConvert/DWIConvertLib.cxx:130:
itk::ERROR: Exception creating converter
itk::ExceptionObject (0x25a1550)
Location: "unknown"
File: /work/Stable/Slicer-4101-build/BRAINSTools/DWIConvert/NRRDDWIConverter.cxx
Line: 91
Description: itk::ERROR: ERROR Reading NRRD File : ~/QC/checked/p1_QCed.nrrd

Thanks a lot.
Esin